1. Field of the Invention
The present invention relates to a lens moving device which is provided in a digital camera, for example, to move a photographing lens along the optical axis thereof.
2. Description of the Related Art
Conventionally, there is known a lens moving device, mounted in a digital camera, which is constructed in such a manner that a cam follower, provided on a support mechanism of a lens, is engaged with a cam surface of a cam gear rotated by a motor. Namely, the lens is moved along the optical axis by the rotation of the cam surface. The cam gear is usually molded from synthetic resin. Generally, a portion corresponding to an injection mouth (provided in a mold to inject melted synthetic resin into the mold) is formed on a member molded from the synthetic resin, as a gate mark. If this gate mark is recessed, the cam follower may engage the gate mark, which may cause the cam gear to stick. Therefore, the gate mark is formed on an area (or non-operative area) of the cam gear, where the cam follower does not engage in a normal operation.
However, if the motor overruns a predetermined drive amount, the cam follower may enter the non-operative area, which may cause the cam follower to stick in the gate mark. If the cam follower sticks in the gate mark, the movement of the lens is stopped.
Therefore, an object of the present invention is to provide a lens moving device in which the cam follower does not engage the gate mark even if the motor overruns.
According to the present invention, there is provided a lens moving device comprising a lens support mechanism, a drive source, a cam member, and a cam follower.
The cam member is provided with a non-operative area with which the cam follower is not in contact during a normal operation. The non-operative area has a gate mark formed during the resin molding process. The stopper prevents the cam follower from interfering with the gate mark. The lens support mechanism supports a lens in such a manner that the lens moves along the optical axis thereof. The drive source moves the lens along the optical axis. The cam member is rotated by the drive source. The cam member is molded from synthetic resin and is provided with a stopper. The cam follower comes in contact with the cam member to transmit the rotational movement of the cam member to the lens support mechanism as a linear movement of the lens along the optical axis. The cam member is provided with a non-operative area with which the cam follower does not come in contact during a normal operation. The non-operative area has a gate mark formed during the resin molding process. The stopper prevents the cam follower from interfering with the gate mark.